This invention relates to electronic learning aids, teaching machines and electronic training aids. More specifically, this invention relates to electronic learning aids, teaching machines and electronic training aids directed to mathematical problems and the solutions thereof, wherein means for producing synthesized speech is provided to present the mathematical problems in audibly voided words and phrases in a manner intended to facilitate the development of arithmetic skills in an operator, particularly the ability of the operator in perceiving mathematical problems in an audibly verbalized form.
Electronic learning aids for teaching subject matter of general character have been equipped with audio means, wherein the audio means is a prerecorded series of spoken messages relating to the subject matter on which the operator of the learning aid is to be tested. In such instances, the audio means often takes the form of a tape recorder. As to electronic learning aids specifically intended to improve arithmetic skills, heretofore such electronic arithmetic learning aids have relied upon a visual display to present arithmetic problems for solution by an operator. When some form of audible means has been associated with such electronic arithmetic learning aids, it typically comprised a sound generator for producing tones indicative of correct answers--rather than prerecorded speech.
Thus, previous electronic learning aids directed to the improvement of arithmetic skills have lacked the special appeal that audibilized speech in presenting arithmetic problems to be solved and the solutions thereto can provide to an operator.
The prior art suggests various techniques for synthesizing human speech from digital data. For instance, some of the techniques used are briefly described in "Voice Signals: Bit by Bit" at pages 28-34 of the October 1973 issue of IEEE Spectrum. An important technique for synthesizing human speech, and the technique used by the speech synthesizer chip of the electronic arithmetic learning aid described herein, is called linear predictive coding. For a detailed discussion of this technique, see "Speech Analysis and Synthesis of Linear Production of the Speech Wave" by B. S. Atal and Suzanne L. Hanauer which appears at pp. 637-50 of Volume 50, No. 2 (part 2) of the Journal of the Acoustical Society of America.
In U.S. patent application Ser. No. 905,328 filed May 12, 1978, now U.S. Pat. No. 4,209,844 issued June 24, 1980, a lattice filter for generating digital signals useful in producing synthesized human speech and capable of being implemented on a single semiconductor chip is described. The arithmetic learning aid described herein makes use of the lattice filter described in the aforementioned U.S. Pat. No. 4,209,844.
It is an object of the invention to provide an electronic arithmetic learning aid having a memory having digital data stored therein from which a plurality of mathematical problems may be derived from presentation to an operator for solution, wherein at least some of the mathematical problems involve respective sets of at least two individual numbers from which the operator is expected to determine a particular mathematical relation in providing a solution to the corresponding mathematical problem, means for randomly selecting a plurality of numbers including at least first and second numbers corresponding to digital data as stored in the memory in deriving a mathematical problem for solution, presentation means for posing a particular mathematical relationship concerning the plurality of randomly selected numbers in presenting the mathematical problem to the operator for solution, operator input means for receiving an input from an operator indicative of a posed solution to the mathematical problem as presented by the presentation means, and digital logic means including comparator means for determining the accuracy of the input from the operator in relation to the correct solution to the presented mathematical problem. In a specific aspect, the presentation means is implemented as a speech synthesizer device and audio means operably associated therewith such that the mathematical problems are presented to the operator as audibly voiced words and phrases posing a particular mathematical relationship involving the relative magnitudes of the plurality of numbers are randomly selected by the random selection means.
It is another object of this invention to provide an electronic arithmetic learning aid having a memory in which digital data of the character previously described is stored in operable association with a speech synthesizer and audio means such that a mathematical problem is audibly voiced to the operator as a posed mathematical relationship concerning whether one randomly selected number group including at least one individual number is greater than or less than other randomly selected number groups.
It is another object of this invention to provide an electronic arithmetic learning aid for testing the ability of an operator to identify an unknown number, whereby the unknown number is randomly selected by a random selection means from a memory having digital data stored therein from which mathematical problems respectively involving the random selection of an unknown number may be derived. The operator is expected to identify the unknown number by proposing a trial number via operator input means, the trial number being compared to the correct identity of the unknown number by a comparator means, and the results of the comparison being audibly announced to the operator by a speech synthesizer device and audio means operably associated therewith.
It is yet another object of this invention to test an operator's ability to determine the identity of an unknown number as randomly selected from memory in an electronic arithmetic learning aid, wherein the arithmetic learning aid is equipped with a comparator, a visual display and a speech synthesis device for comparing a trial number proposed by the operator in an effort to identify the unknown number and introduced via operator input means with the correct identity of the unknown number, wherein the visual display and the speech synthesis device both visually and audibly present the results of the comparison by providing an informational clue as to the identity of the correct number.
The foregoing objects are achieved as is now described. The words and arithmetic problems to be utilized by the electronic arithmetic learning aid are stored as digital codes in a memory device. This memory is preferably of the non-volatile type so that the data is not erased when power is disconnected from the arithmetic learning aid. In the specific operational embodiments according to the present invention, the memory has digital data stored therein from which a plurality of mathematical problems may be derived for presentation to an operator for solution. In one aspect, at least some of the mathematical problems involve respective sets of at least two individual numbers from which the operator is expected to determine a particular mathematical relation in providing a solution to the corresponding mathematical problem. In another aspect, the mathematical problems respectively involve the random selection of an unknown number which the operator is expected to identify by proposing a trial number. A speech synthesizer circuit is connected to the output of the memory for selectively converting some of the signals stored therein to speech signals from which audible speech stating arithmetic problems, the solutions thereto, and associated comments is generated. Several types of speech synthesis circuits are known and could be employed in the electronic arithmetic learning aid. In a disclosed embodiment of the electronic arithmetic learning aid, the speech synthesizer thereof is implemented as an integrated circuit on a single semiconductor chip and employs a linear predictive coding technique in synthesizing speech. A speaker is provided to convert output from the speech synthesizer to audible sounds. A keyboard and display, both of which preferably are capable of accommodating alphanumeric characters, are preferably provided. The display and keyboard are preferably coupled to the speech synthesis circuit and memory via digital logic means in the form of a controller circuit. In the embodiment disclosed, the controller circuit is an appropriately programmed microprocessor device. The controller circuit controls the memory to read out the digital signals corresponding to the words, phrases and arithmetic problems to be utilized, the words and phrases preferably being randomly selectable from a plurality of words stored therein. The digital signals representative of the words and phrases are converted to audible voiced words and phrases by means of the synthesizer circuit in combination with the speaker. The controller circuit is also effective to pose random arithmetic problems to the operator, either verbally via speech synthesis or by means of the display. The correct answer to a particular arithmetic problem is also stored, and may be compared with the proposed answer which is input by the operator at the keyboard. The operator may be informed audibly of the results of the comparison via the speech synthesis circuit and speaker. The arithmetic learning aid is installed in an easily portable case. The size of the speech synthesis chip included as a component thereof is on the order of 45,000 square mils using conventional MOS design rules and a convention P-MOS processing technique. Of course, using C-MOS processing would tend to increase the size of the chip somewhat.
In one operational embodiment of the electronic arithmetic learning aid according to the present invention, a plurality of numbers including at least first and second numbers corresponding to digital data as stored in the memory are randomly selected to derive a mathematical problem, and the operator is requested via the speech synthesis device and audio means operably associated therewith to determine whether the first randomly selected number is greater than or less than the second randomly selected number in presenting the randomly selected numbers as a mathematical problem to the operator for solution. In another operational embodiment, the operator is tested on his ability to determine the identity of a randomly selected unknown number corresponding to digital data as stored in the memory, wherein the operator inputs a trial number via the operator input means indicative of a proposed identification of the unknown number. The comparator of the electronic arithmetic learning aid in this operational embodiment thereof determines the appropriateness of the input received by the operator input means. Means coupled to the comparator produces an indication of the accuracy of the input from the operator as received by the operator input means in relation to the correct identity of the unknown number and causes the presentation means including a visual display and a speech synthesis device to both visually and audibly provide digital information as a clue bearing upon the identity of the unknown number. Specifically, the visual display and the speech synthesis device visually and audibly provide first and second digits, wherein the first digit is representative of the number of digits in the trial number that occur in the unknown number regardless of position, and the second digit is representative of the number of digits in the trial number that are correctly positioned as to sequence. Thereafter, the operator continues to input additional trial numbers via the operator input means as a proposed identification of the unknown number until it is correctly identified, with the visual display and the speech synthesis device presenting up-dated versions of the first and second digits reflective of subsequent trial numbers proposed by the operator via the operator input means.